The present invention relates generally to a radial piston machine, and more particularly to an improvement in the components of a radial piston machine.
Radial piston machines are so well known as to their general construction and operation that a detailed resume thereof is not required in the context of this disclosure. However, it is necessary to point out that such radial piston machines generally utilize a stationary member, a cylinder body which rotates about the stationary member and is provided with cylinder bores, pistons which are reciprocably guided in these bores, a piston-control ring which is adjacent the cylinder body, and glide shoes provided on the pistons and in sliding engagement with the control ring. According to the prior art it has been proposed to provide the relatively movable surfaces of these various components in a radial piston machine, surfaces which are of course subjected to a high degree of wear, with a glide layer which may be of bronze or brass. Of course, the application of such a layer requires a considerable increase in the complexity of manufacturing the radial piston machine and, thus, in the expenses of manufacture. Moreover, it has been found that the materials proposed for these glide layers are not capable of withstanding the high pressures which frequently obtain in the radial piston machines now in use. Moreover, there are also certain circumstances in which the copper contained in the materials proposed for the glide layer may react chemically (and deleteriously) with the fluid medium being pumped, if the radial piston machine is used as a pump.